Leather composition



ev l

minute the mass. of the .templated that the outer surfaces thereof are smoothly unctuous like natural leather, as distinguished from artificial leather compo Patented Oct. 27, 1931 if -PJIUNETED STATES. PATENT OFFICE I VGVUSTAVE' DANIEL FORTMAN, or PHILADELPHIA, PENNSYLVANIA LEATHER COMPOSITIO N Nof Drawing.

In every process of manufacture of articles of leather, for instance, shoes, belts, trunks, suitcases, hand bags, etc., there is a large percentage of clippings too small to make any leatherlarticle, and such leather scrap is wasted except as it may be utilized for fertilizer or made into charcoal for heat treatment of ferric metals. It is the object and eflectof'my invention to utilize such leather scraps, for any purpose for which the original leather web may be used, by uniting such scraps in substantially homogeneous webs, or other forms; the process of my inventlon hereinafter described being operative to not only produce leather compositions respectively resembling the various commercial forms of natural leather, having various degrees of hardness and flexibi1ity,flbut to produceother compositions which are much harder. and more durable than any natural leather and more in the nature of horn.

In efiecting by invention, I prefer to grind, or otherwise comminute, the leather scraps to such a degree that a. mass thereof seems to be of uniform texture when passed between the fingers of the operator, for the reason that when reduced to such state, the

product is smoothly homogeneous. However,

it is unnecessary to thus uniformly comleather ingredients of my composition, which may be in the form ofirregular shreds mixed with flocculent particles, or otherwise. However, when the leather is used in such-irregular form, there are correspond ing irregularities in the product, but that is .desirable for production of webs having an irregular, instead of a smooth, surface. 7

The comminuted leather, in any form above contemplated, is integrated in a. tenaciously coherent, more or less elastic and flexible web or other form by a binding medium which is primarily'a liquid but which solidifies in the product to-a tough horn-like substance extending between and uniting-the particles of the leather in a substantially homogeneous However, it s characteristic of all products of my 1I1V6I1l31011 herein con- ,tion of the hydrocarbon,

Application filed March 21, 1928. Serial No. 263,603.

sitions of the prior art which are sticky my products being tenaciously coherent an cohesive, but not adherent or adhesive, to anything with which they come in contact.

I have found it convenient to make such binding material by mixing commercial cottage cheese with commercial aqua ammonia in the proportion of five pounds of cheese to one pint of the ammoniacal liquid. The effect of thus alkalinating the cheese is to more or less saponify the fatty constituents thereof. After that mixture has been allowed to stand for about two hours, I thoroughly mix one ounce of hydrochloric acid therewith. Such acidulation of the mass substantially neutralizes its alkalinity. The addition of the acid causes a chemical reaction with the ammonia throughout the mixture with production of fumes which are extremely acrid and should be avoided by the operator. IVhen such reaction is completed, the mass is allowed to dry and, when dried, resembles horn; being principally gelatinized casein. That dried material is then dissolved in benzol (a hydrocarbon distillate of petroleum otherwise known as benzene C H until it forms a gummy liquid, the viscosity of which varies with the proportion of the solid matter dissolved in the hydrocarbon.

The leather, in any comminuted form above contemplated, is then mixed with the gummy binding liquid aforesaid in such proportions as to coat the particles of leather and form a film between them when they are pressed together in a dough-like mass, which may be kneaded or otherwise manipulated or agitated until of substantially uniform consistency. The resulting plastic mass may then be rolled or pressed to form a plane sheet or web of any desired extent, or may be otherwise shaped by hand, or in a mold, or by any other suitable means, and may be permitted to dry spontaneously by evaporaor may be warmed to accelerate its desiccation. The residue of the binding medium above described is pliable and more or less elastic, but harder than the leather particles mixed therewith. Consequently, the degree of hardness of the prodleather particles and uct' may "be determined and varied in ac- "cordance' with the proportion of the binding material residue left in a given mass of comminuted leather. For instance, from the same comminuted leather, 1 may produce a thin flexible Web resembling soft tanned calfskin, such as is used for shoe uppers -ora thicker harder and tougher vveb resembling sole'leather; the latter having more binding material per unit, of volume than the soft. product aforesaid;

Moreover, the degree of hardness of a i i which are known to the trade as benzine and rw ic m yl eusedas a Solvent of l eized; binding material of the given composition of leather and binding inaterial may be increased byforming-theproduct under Water, which penetrates the 'tvhen evaporated, leaves such particles in a harder stiffer state than particles which have not been wet sufoh hardening effect" being similar tothat produced n onnatararleather by wetting and dryingi "1 a a Although--I-*find itconvenient to mix the composition aforesaid of the consistency of dough forthe formation of webs thereof by rolling o1; pressing means; I do not desire to limit myself to that method of procedure, for a composition in accordance With my in ventioninay, be primarilyof the consistency of paint soy-that itm'ay be'spread tosthe' desiredfjform byatmshing operation Such a v paint like consistency attained by f the use of in'o're of theihydrocarbon solvent of the casein than isnsedin t i r V dough-like consistency-s "e composition-0f a In other words, the viscosity of the'miXt'ure' rnay be?Wtried at the convenience of the operator ;in accordance With-thefprop ortion of the solvent employed. However, the solvent being volatile', the consisten'cyfof the resulting 'roduct" is "deter- .niined'by the proportion o" the solutewhich is, left in -th'e'--'composi;t ion and not by. the

*quan'tityfbf the volatile 'solvent,*"vvh ich fis m'erel'v'a convenient medium for manipulating the residual ingredients during the *process of manufacture of the products aforesaid; j

i 'Itischaracteristicof allcfthe composi- 7 use commercial tions of my invention herein conternplatedV "that they are Water-proof, in the sense that disintegrated by I immersion in they are so "far" resistant to the action of electricity as tobe classed as they are not dielectrics? V r Alth'ou'ghfl have founditconvenient to cheese as the source of the ingredient of my com ositio f of casein I V I may produce casein directly from course,

cows' milk by skimming 'the "cream therefrom allowing the skimmed milk tos'tand in a Warm place'unti'l it curdles; then 'sep-, 'aratin'g-thecurds fro m'the Whey by percolationthrougha filter-mi er OIOthBI suitablematerial, and Washing the curds 'W'i'th vtaterfto Eeliiniiiate "the lactic acid therefrom.

* "Then th cards; may

horn-like consistency fitocasein thus produced.

ivv-ithout departing from corresi've'and inc-riotous,

' nuted leather particles 7 cornminuted to be' xvra ped in a'cloth solved m te-112011 andboiled to remove the fat, and dried to' a such residue being substantially pure casein. I I

Although'l have found it convenient to produce the binding material aforesaid from casein which is formed by first alkalinating and "then acidulating and then desiccating miik cu'rds,l do not desire toilii'nit myself Moreover, I preferto use the highgrade hydrocarbon benzclyitis mucir-inore-costly than the similar hydrocarbons, of varyingcomposition,

casein to produce a general character above contemplated.

Iain aware that't is not new to forma cementiti'ous material of gelatinizedcasein. However, the heretofore known solvents of such casein, such as strong acids,'ralkalis,zand

the, primarily separate and distinct par ticle's of leather in a substantially homo geneeas mass resembling natural leather, all of the-phy ical qualities-of the laftter, in-

although cludi ng'such 'su rfacetens'ionias'to render the Without-any tendency to adhere to any-thing withwhich'it eome'sin "contact,- a

- Th'lfBflG-yl d0310b desire to nma myself tothe precise details 'of the process or product herein-set forth, as it i various modifications may :be made therein the essentiai features of my invention, as defined in the appended claims, I I 7 lclai'mz 1-.fAc0mposi-tion of matter, which is nonincluding comminutedleather particles comminnted to "such 'a; degree that a mass thereof seems' to or uniform texjture'when passed between the fingers of the oper ato rysaid particles being connected by abinding medium including the residue ofcasein alkalinated an'da' idulate-awe chemically neutral and dissolved ina volatile hydroc'arbom v 2; Ac'om'po'sition of matter"; which isnoncorrosive and 'inodc'rous including commisuch a degree that a inassfther'eof seems to be of uniform texture When passed between the fingers of the operator, said particles connected by a bindin anediuln including the residueef casein alkal inated undecidelate'd' to a chemically surface thereof unctuous likenaturai leaither,

obvious that neutral state we 'ilisseems to be of uniform 3. The process of forming a leather composition which is noncorrosive and modorous, and which mcludes II11X1I1g cottage cheese with aqua ammonia in the prop0r-;

tions of five pounds of cheese to one pint of ammonia liquor; then adding hydrochloric acid and agitating the mixture until it is substantially uniform and in a chemically neutral state; allowing said mass to dry; dissolving the dried mass in benzol until it forms a gummy binding liquid; then mix ing said binding liquid with a mass of comminuted leather particles comminuted to such a degree that a mass thereof seems to be of uniform texture when passed between the fingers of the operator; shaping the product to the desired form and desiccating it.

4. The process of forming a leather composition Which is noncorrosive and inodorous, and which includes mixing cottage cheese with sufficient aqua ammonia to saponify the fatty constituents of the cheese; then adding hydrochloric acid to neutralize the alkalinity of the mass and agitating the mixture until it is substantially uniform; allowing said mass to dry; dissolving the dried mass in a volatile hydrocarbon distillate of petroleum until it forms a gummy binding liquid; then mixing said binding liquid with a mass of comminuted leather particles comminuted to such a degree that a mass thereof texture when passed between the fingers of the operator; shaping the product to the desired form and desiccating it.

5. The process of forming a leather composition which is noncorrosive and inodorous, and which includes dissolving gelatinous casein in a volatile hydrocarbon, forming a gummy binding liquid; and then mixing said binding liquid with a mass of comminuted leather particles comminuted to such a degree that a mass thereof seems to be of uniform texture when passed between the fingers of the operator,

6'. The process of forming a leather composition which is noncorrosive and inodorous, and which includes dissolving gelatinous casein in benzol, forming a gummy binding liquid; and then mixing said binding liquid with a mass of comminuted leather particles comminuted to such a degree that a mass thereof seems to be of uniform texture when passed between the fingers of the operator.

In testimony whereof, I have hereunto signed my name at Philadelphia, Pennsyl- Vania, this nineteenth day of March, 1928.

GUSTAVE DANIEL FORTMAN. 

